The following is a tabulation of some prior art that presently appears relevant:
U.S. PatentsPatent NumberKind CodeIssue DatePatentee8,035,388B22011 Oct. 11Casanova8,148,988B22012 Apr. 3Blumich2,545,994A1948 Mar. 6Gabler3,676,791A1970 Mar. 17Guenard5,247,935A1992 Mar. 19Cline2,993,638A1957 Jul. 24Hall4,415,959A1981 Mar. 20Vinciarelli2,442,762A1943 Sep. 9Ellis1,862,559A1931 Aug. 14White4,075,042A1973 Nov. 16Das4,342,608A1980 Apr. 21Willens5,867,026A1996 Apr. 4Haner7,145,340B22004 Nov. 4Rindlisbacher7,135,865B22004 Mar. 22Park6,396,274B11999 Nov. 5Commens9,607,740B22014 May 6Rowe
U.S. Patent Application PublicationsPublication Nr.Kind CodePubl. DateApplicant13397273A12011 Feb. 22Koseoglu14394976A12012 Apr. 16Hong13164495A12005 Oct. 27Baker12153349A12007 May 21Kitagawa
Foreign Patent DocumentsForeignDoc. Nr.Cntry CodeKind CodePub. DtApp or Patentee001651PCTA12009 Apr. 3Prisner